If you’re talking about the “book” by “Deese Hopkins”, I doubt AI slop from someone who doesn’t exist is going to help them much. (Even the profile picture on Amazon is clearly AI-generated - stylegan2 based on the watermark.)
If you absolutely need a paper back, I’d take one of the open source books available and send it to a softcover printing service. There are some that do single unit 150 pages for less than €10 incl. shipping in Germany (might obviously differ in your country). Wombat’s Book on Nix has a PDF version, for example:
Wow, things are tight here. I am relatively new to NixOS and found the content at least somewhat useful. Didn’t mean to ruffle any feathers, get spam warnings, or promote “slop”.